Method and apparatus for treating and drawing synthetic filament yarns



1366- 1963 A. c. COGGESHALL METHOD AND APPARATUS FOR TREATING ANDDRAWING SYNTHETIC FILAMENT YARNS Filed NOV 28 1960 CONDENSATE H y n E mm i c m A United States Patent 3,114,999 METHOD AND APPARATUS FORTREATING AND DRAWING SYNTHETIC FILAMENT YARNS Alva C. Coggeshall,Pensacola, Fla, assignor, by mesne assignments, to Monsanto ChemicalCompany, a corporation of Delaware Filed Nov. 28, 1960, Ser. No. 72,1375 Claims. (Cl. 57-555) This invention realtes to a method and apparatusfor treating and drawing synthetic filament yarns formed from athermoplastic polymer such as nylon. More particularly, this inventionrelates to a novel method and apparatus of the above type utilizingporous means to steam treat and to localize the stretch point of yarn,concurrently, for improving drawing performance and reducing theincident of yarn breakage during the drawing process.

Newly formed nylon yarn produced by melt spinning is known to haverelatively low strength. To increase its tensile strength undrawn yarnis stretched or drawn whereby molecules forming the yarn are aligned ororiented in the general direction of the yarn axis. In usual practice, afeed roll and a draw roll, driven at different peripheral speedsrelative to each other and geared to a predetermined draw ratio, areemployed to draw yarn. Usually, a brake device is positioned between thefeed and draw rolls to localize the stretching point of the yarn.

Yarn drawn in the usual manner is subjected to high stresses andfrequently the drawing load applied exceeds the breaking load of theyarn, in which case, the yarn is broken, generally, in the vicinity ofthe brake device. Yarn breakage interrupts the drawing process andcauses costly delay in operation.

To overcome the problem of yarn breakage within a draw zone, vapor inthe form of steam applied to the yarn at the localized stretch pointwill produce beneficial changes therein, improving its drawingperformance such that the frequency of yarn breakage is reduced.

It is an object of this invention to provide novel apparatus for drawingand steam treating synthetic textile yarns formed of a thermoplasticpolymer such as nylon, whereby the draw performance of the yarn isimproved. It is another object to provide apparatus of the typeutilizing unitary brake means, formed of a porous material resistant toabrasion, to establish a steam zone thereabout and to fix the stretchpoint of yarn within a draw zone. Another object is to provide novelapparatus for treating and drawing yarn including porous brake meansadapted to receive steam interiorly thereof and to discharge condensatetherefrom. Another object is to provide a novel method of treatingtextile yarns with a fiuid medium at the localized stretch point thereofto incorporate beneficial changes in the properties of the yarn forimproving the latters drawn performance. Another object is to provide amethod of treating nylon yarn with steam to render the yarn moreresistant to breaking by passing the yarn through a steam zone at thepoint of localized stretching thereof. A still further object is toprovide a novel method and apparatus for simultaneously steam treatingand drawing synthetic textile yarns formed from a thermoplastic polymersuch as nylon by simple and inexpensive means to minimize yarn breakage.

According to the invention, a novel method and apparatus for treatingand drawing yarn that accomplishes the above objects are provided. Ingeneral, the apparatus embodying the invention comprises two spacedrolls, each positively driven at different peripheral speeds relative toeach other, and brake means interposed in the path of a yarn lacedbetween the rolls, said brake means being formed of a porous materialresistant to abrasion having an inlet and an outlet therein forconducting steam from 3,114,999 Patented Dec. 24, 1963 a suitable sourcethereto and removing condensate therefrom, respectively. Preferably, theslower positively driven roll cooperates with a corresponding rotatableroller arranged in parallel and contacting relation therewith to providea feed roll assembly for imparting an initial predetermined rate oftravel to a yarn passed between the rolls of the assembly, andpreferably, a spacer roll is positioned near the faster positivelydriven roll to prevent yarn wrapped around the spacer roll and thefaster driven roll from becoming superimposed. It will be noted that,when the inlet of said brake means is pressurized with steam, said brakemeans will provide a steam zone or area thereabout since steam will passthrough the pores of the wall of the brake means and escape into thesurrounding atmosphere. In general, the novel method for drawing andtreating nylon yarn comprises delivering yarn at one rate of speed to adraw zone, simultaneously localizing the stretch point of the yarn andpassing the yarn through a steam area within the draw zone, withdrawingthe yarn at a second higher rate of speed from the draw zone, and takingup the yarn in an orderly manner whereby the drawing performance of theyarn is improved and the incident of yarn breakage is reduced.

Other objects and advantages of the present invention will becomeapparent from a study of the following speci fication, claims, anddrawing wherein:

FIGURE 1 is a schematic view showing, in perspective, the novelapparatus comprising the invention in operative arrangement; and

FIGURE 2 is a longitudinal sectional view of the draw pin 9, shown inFIGURE 1, drawn to a larger scale.

In the several figures in the drawing like parts are designated by thesame reference numerals for reasons of simplicity and convenience.

Referring to the drawing, the novel apparatus for treating and drawingyarn embodying the invention is shown in FIGURE 1 with the respectivecomponents thereof arranged in the positions in which they wouldordinarily be suitably mounted on a framework, omitted for purposes ofsimplicity. An undrawn filament yarn 1, of polymeric composition such asnylon and supplied from a supply package or bobbin 2, is shown lacedwithin the novel apparatus according to the method of the invention tobe explained hereinafter.

A snubbing bar 3 of conventional type may be suitably mounted nearbobbin 2 to assist in maintaining an orderly and uniform supply of yarn.A pigtail guide 4 is positioned below bar 3 and serves to guide the yarnin its downward path to a feed roll assembly 5.

The feed roll assembly 5 includes a pair of parallel rotatably mountedcorresponding rolls 6 and 7, roll 7 being driven by suitable powermeans, not shown, at a predetermined rate of speed. Rolls 6 and 7 haveperipheral surface contact therebetween so as to nip the yarn passedbetween the rolls for imparting an initial rate of speed or travel,corresponding to the speed of driven roll 7, to the yarn and to causeroll 6 to rotate correspondingly with roll '7 but, in a reversedirection therefrom.

A draw roll 8 is rotatably mounted below feed roll assembly 5 and isdriven by suitable power means, not shown, at a higher peripheral rateof speed than that of roll 7, and applies a stretching or pulling forceto the yarn when the latter is laced from the feed roll assembly 5 toand around roll 8. Drawing or stretching produces molecular orientationwithin and increases the tensile strength of the yarn.

An elongated, preferably hollow, member or draw pin 9, FIGURE 2, fixedlymounted at the end nearest roll 8 as shown in the drawing, is interposedin the path of yarn 1 intermediate the feed roll assembly 5 and the roll8, and serves to localize the stretching point of the yarn when thelatter is pulled therearound. Member 9 includes a tubular element 10formed of a porous material resistant to abrasion and a pair of end caps11 having transverse openings therethrough. End caps 11 are held intightly clamped relation on the ends of element 10 by a nut 12 havingscrew-threaded engagement with one end of an elongated bolt 13 extendingaxially through element 10 and end caps 11.

The ends of a pair of lines or pipes, 14 and 15, extend into theinterior of draw pin 9 at the mounting end thereof through respectivetransverse openings through the wall of one of the caps 11. Line 14 isnormally supplied with steam from a suitable source, the steam flowinginto the interior of element 10 and forming a steam zone surrounding theimmediate exterior area of the draw pin by passing through the pores inthe wall of element It). Line 15 is provided to carry off condensateforming in the interior of element 10 and preferably, does not extendinwardly thereof as far as line 14 does so as to prevent accumulation ofcondensate within element 10.

Draw pin 9 is normally mounted in an inclined position in relation tothe axis of roll 7 to prevent the wraps of yarn passed around member 9from becoming superimposed and is positioned so that line 15 is belowline 14 to permit condensate to flow by gravity to line 15.

Draw pins of the ordinary solid wall type are generally manufacturedfrom a material resistant to abrasion hearing the trademark Alsimag, theprincipal ingredient of the material being aluminum oxide or titaniumdioxide. Alsimag is here mentioned as one material from which tubularelement 10 may be manufactured since Alsimag can be produced in a porousform while still retaining the quality of abrasion resistance.

Preferably, an inclined rotatable spacer roll 16 suitably mounted at oneend thereof and positioned near draw roll 8 is provided to prevent theyarn from wrapping in superimposed manner on draw roll 8.

A ring twisting assembly 17 is provided to collect the yarn andcomprises a pirn 18 adapted to be rotated by suitable means and avertically reciprocable spinning ring 19 carrying a ring traveler 20adapted to revolve freely about the pirn 18 as the yarn is twisted adesired amount and wound on the pirn.

A guide 21 is interposed between draw roll 8 and as sembly 17 to guidethe yarn to the assembly 17.

In operation, line 14 is pressurized with steam from a suitable source.Yarn 1 is withdrawn from one end of bobbin 2 and threaded conventionallyaround snubber bar 3, then led through pigtail 4, and passed betweenrolls 6 and 7 of assembly 5, the yarn being caught or nipped betweenrolls 6 and 7 and given an initial traveling speed corresponding to thepredetermined speed of driven roll 7.

From assembly 5 the yarn is delivered to and led around draw pin 9 adesired number of turns. In passing around draw pin 9, the yarn passesthrough a controlled steam area surrounding pin 9 since the steamsupplied to line 14 will enter draw pin 9 and flow to the exteriorthereof through the pores of element 10. The steam acts to plasticizeand condition the yarn for improving its drawing performance. From drawpin 9 the yarn is directed to and around draw roll 8 and spacer roll 16,collectively, a desired number of turns for imparting a greater speed oftravel to the yarn since roll 3 is driven at a higher predeterminedspeed than roll 7 and according to a predetermined draw ratio. Due tothe differential rates of peripheral speeds of rolls 7 and 8, a highstress is applied to the yarn whereby the latter is attenuated, theattenuation being concentrated or localized at the pin 9 which serves asa brake. Treating the yarn with steam at the pin 9 reduces thelikelihood of the yarn being broken at this point since steam applied tothe yarn substantially simultaneously while stretching the yarn improvesthe latters extensibility characteristic.

From roll 8 the yarn is threaded through guide 21 and is collected inthe usual manner on pirn 18 of the ring twisting assembly 17 after beingpassed through the ring traveler 20.

Thus, the invention, as described, provides a novel method and apparatusto steam treat a synthetic yarn while at the same time drawing the yarn,by simple and inexpensive means.

It will be understood that the invention is not to be limited to thespecific embodiment shown and described herein, except as defined in theappended claims.

Having described the invention, the following is claimed:

1. Apparatus for treating and drawing yarn, said apparatus comprising incombination stationary porous snubbing means formed of a materialresistant to abrasion and having pores of a perviousness to permit flowof steam therethrough, conduit means associated with said oproussnubbing means for supplying a treating agent interiorly thereof, thetreating agent normally flowing through said pores in said poroussnubbing means to the exterior thereof to form a treating zonethereabout, feed roll means for forwarding the yarn longitudinally atone rate of speed to said porous snubbing means, draw roll means forwithdrawing the yarn from said porous snubbing means at a secondincreased rate of speed for stretching the yarn, said yarn normallybeing laced to slidably engage said porous snubbing means so as,simultaneously, to localize the stretch of the yarn and to uniformlytreat the yarn by direct application of the treating agent thereto.

2. Apparatus for treating and drawing yarn as claimed in claim 1 whereinsaid porous snubbing means comprises a porous snubbing pin.

3. Apparatus for treating and drawing yarn, said apparatus comprising incombination a hollow porous draw pin formed of a material resistant toabrasion and having pores of a perviousness to permit flow of steamtherethrough, a supply conduit having communication with the interior ofsaid hollow porous draw pin and normally being charged with a supply ofsteam for delivering steam to said hollow porous draw pin, the steamnormally flowing through said pores in said hollow porous draw pin tothe exterior thereof to form a steam zone thereabout, a dischargeconduit having communication with the interior of said hollow porousdraw pin and serving to remove condensate from the interior thereof,feed roll means for advancing said yarn longitudinally at one rate ofspeed to said hollow porous draw pin, draw roll means for withdrawingthe yarn from said hollow porous draw pin at another rate of speedfaster than said one rate of speed for stretching the yarn, said yarnnormally being laced to frictionaly engage said hollow porous draw pinso as, simultaneously, to localize the stretch of the yarn and to treatthe yarn by direct application of steam thereto.

4. Apparatus for treating and drawing yarn, said apparatus comprising incombination, a draw pin having a tubular member formed of a porousmaterial resistant to abrasion and having pores of a perviousness topermit flow of steam therethrough, a pair of end caps each arranged at arespective end of said tubular member, clamping means for securing saidend caps on said tubular member, a supply conduit having communicationwith the interior of said tubular member and normally being charged witha supply of steam for conducting steam to said tubular member, adischarge conduit having communication with the interior of said tubularmember and serving to remove condensate from the interior thereof, feedroll means for advancing said yarn longitudinally at one rate of speedto said draw pin, draw roll means for withdrawing the yarn from saiddraw pin at another rate of speed faster than said one rate of speed forstretching the yarn, said yarn normally being laced to frictionallyengage said tubular member so as, simultaneously, to localize thestretch of the yarn and to treat the yarn by direct application of steamthereto, and an inclined spacer roll positioned near said draw rollmeans for preventing the yarn from wrapping in superimposed manner onsaid draw roll means.

5. A method for treating with steam synthetic filament yarn undergoingsnubbing comprising delivering the yarn at a first rate of speed to adraw zone, withdrawing the yarn at a second increased rate of speed fromsaid draw zone so that the yarn is stretched a predetermined amountwithin said draw zone, snubbing the travel of the yarn between saiddelivery and Withdrawal points by slidable engagement with a stationaryporous surface, applying steam directly and uniformly to the yarnthrough said porous surface at the point of said slidable engagement ofthe yarn therewith, and taking the yarn up in an 15 orderly manner afterbeing withdrawn from said draw zone.

References Cited in the file of this patent UNITED STATES PATENTS2,309,771 Jordan Feb. 2, 1943 2,491,569 Lichtenberg Dec. 20, 19492,778,058 Gabler Jan. 22, 1957 2,864,931 Stoddard et a1. Dec. 16, 19582,874,410 Kinney Feb. 24, 1959 2,894,802 Braunlich July 14, 1959 FOREIGNPATENTS 806,532 Great Britain Dec. 31, 1958 338,922 Switzerland July 31,1959

1. APPARATUS FOR TREATING AND DRAWING YARN, SAID APPARATUS COMPRISING INCOMBINATION STATIONARY POROUS SNUBBING MEANS FORMED OF A MATERIALRESISTANT TO ABRASION AND HAVING PORES OF A PERVIOUSNESS TO PERMIT FLOWOF STEAM THERETHROUGH, CONDUIT MEANS ASSOCIATED WITH SAID OPROUSSNUBBING MEANS FOR SUPPLYING A TREATING AGENT INTERIORLY THEREOF, THETREATING AGENT NORMALLY FLOWING THROUGH SAID PORES IN SAID POROUSSNUBBING MEANS TO THE EXTERIOR THEREOF TO FORM A TREATING ZONETHEREABOUT, FEED ROLL MEANS FOR FORWARDING THE YARN LONGITUDINALLY ATONE RATE OF SPEED